Very high energy γ ray absorption by the galactic interstellar radiation field
Key laboratory of particle astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918-3, Beijing 100049, PR China
Accepted: 14 December 2005
Aims.We calculate the attenuation of very high energy γ rays from Galactic sources.Methods.A recent calculation of the Galactic interstellar radiation field shows that the infra-red radiation background near the Galactic Center is very intense. The attenuation of very high energy γ rays by this radiation is strong and occurs at lower energies than previously thought.Results.Our result shows that the cutoff of the high energy γ ray spectrum begins at about 20 TeV and reaches about 10% for 50 TeV γ rays.
© ESO, 2006